276 MAN --AN ADAPTIVE MECHANISM 



we found that the intravenous injection into the mother 

 (rabbit) of extract of her own placenta produced typi- 

 cal work changes in the organs of the kinetic system. 

 (Fig. 68.) Thus, we have direct physical evidence to 



A. 



Section of normal cerebellum 

 of cat. 



B. 



Section of cerebellum of pregnant 

 cat. 



FIG. 68. EFFECT OF PREGNANCY ON THE BRAIN-CELLS OF A CAT. 

 The effect of the long activation of pregnancy is well illustrated by the 

 generally disorganized appearance of the Purkinje cells in B. 



(From photomicrographs, X 310.) 



confirm and support the experiences of everyday life. 

 The reason why there are changes in the brain-cells 

 and why there is evidence of fatigue is because the 



